1. Field of the Invention
The present invention relates to an organic light emitting device that includes an anode, a cathode, and a light emitting layer disposed between the anode and the cathode, wherein the cathode includes a plurality of metal layers.
2. Description of the Related Art
With the advent of the 21st century, the trend toward an information-oriented society has been accelerated, and along with a necessity for receiving and transmitting information anytime anywhere conventional cathode-ray tube (CRT) displays are being replaced with flat panel displays. One of the most common types of flat panel displays currently used are liquid crystal displays (LCD). This is because LCDs are lightweight and have low power consumption. However, since a LCD is not a self-light emitting device but a light receiving and emitting device, the LCD has technical limitations in terms of contrast ratio, a viewing angle, and area size. Accordingly, new flat panel displays that can overcome such technical limitations are being developed worldwide. One such new flat panel display is an organic light emitting diode (OLED). The OLED can be driven at low power, has a wide viewing angle and quick response speed, and is self-light emitting, light weight, and thin. Accordingly, was of OLEDs is being increased in Japan, Korea, and the US.
A cathode of an active matrix organic light emitting device (AMOLED) used in current mobile displays is formed of a composition including magnesium (Mg) and silver (Ag), but when the AMOLED has a size of 14″ or larger, a lower resistance is required. In this regard, an IR drop phenomenon occurs in AMOLEDs of 14″ or larger when the cathode is formed of Mg and Ag.